Dispensing systems in the past have utilized bottles containing quantities of a fluid to be dispensed. In the gravity feed fluid dispensing systems to which the present invention is particularly directed, the bottles are stored in an upright position, then inverted for dispensing of the fluid from the bottle through the dispensing system.
It is important in many applications to accurately control the amount of the fluid that is dispensed. Frequently, such fluids are diluted prior to use, and it is desirable to accurately control the dilution rate, such of for reasons of economy or safety. This has been somewhat difficult to achieve with conventional bottle designs for dispensing systems.
An exemplar bottle is disclosed in U.S. Des. No. 298,514 entitled "Syrup Container or Similar Article". A bottle according to this design patent is available from Soda-Mate Enterprises of Trumbull, Conn. for use with its Model S100 gravity feed fluid dispenser system and has a capacity of 0.667 milliliters. Such bottles are injection/blow molded from a suitable polymeric material, such as high density polyethylene and typically have a wall thickness of 0.018 inches. Bottles of this type, although functional, are somewhat limiting during use since their limited capacity requires replacement or refilling at relatively frequent intervals.
Bottles having larger capacities may be employed. However, in conventional bottles having a larger capacity, the ratio of the wall thickness to the volume is reduced to the point where "paneling" occurs when the bottle is inverted and the fluid contained therein is being dispensed.
For purposes of this invention, the term "paneling" refers to inward and outward deflection in the walls of a bottle in a manner that induces fluctuations in the rate at which fluids are dispensed from a bottle. Paneling typically occurs with a bottle inverted and as the fluid is being dispensed. As the fluid level in the inverted bottle is reduced, a partial vacuum is gradually created in the "headspace" above the level of the fluid within the bottle. The walls of the bottle are gradually deflected inwardly under the influence of the partial vacuum. This deflection acts to enable the flow of the fluid from the bottle. The deflection increases until a point is reached where a quantity of the fluid has been dispensed from the bottle and the walls quickly flex outwardly, whereby the pressure in the head space is equalized with the ambient pressure.
The fluctuation of the flow of fluid from the bottle due to paneling prevents accurate metering of the dispensing of the fluid from the bottle. Furthermore, paneling may be exacerbated if the bottle is manually engaged and squeezed. Paneling is particularly a problem if the bottle is to be used in conjunction with a dispensing system for dispensing the fluid from the bottle in a controlled manner, and also to dilute the fluid with one or more other fluids.
Alternatively, the wall thickness of the larger capacity bottle may be increased to resist paneling. However, this may not be completely successful, and increases the weight and expense of the bottle.
Conventional dispensing systems and bottles for use therewith do not provide a bottle with adequate capacity that avoids the problem of paneling and subsequent inaccurate dispensing of fluids from the bottles.